Scissors extender

ABSTRACT

1,151,889. Fork lift trucks. EATON YALE &amp; TOWNE Inc. 28 July, 1966 [17 Aug., 1965], No. 33933/66. Heading B8H. A load carrier 21 is mounted via a base-plate 14 having rollers 15, 16, for vertical movement on the uprights of an industrial lift truck, the carrier being coupled to the base-plate 14 by means of a scissors linkage 30, 40, 41. The latter comprises two parallel sets of scissor links, each of which comprises a link 30 housing a bearing 42 at its mid length position, and part links 40, 41, each of which has one end secured to the bearing but on opposite sides of the link 30. The end portions of the link 30 are displaced to opposite sides of the plane of the centre portion of the link, allowing the links to pass to over-centre positions when fully retracted. The links are mounted to the baseplate 14 and to a carrier support member 17 by pivots 33, 48a and slide bearings 32, 47. A pair of rams 51, 52 pivotally connected between the links 30 and the support member 17 effect the projection and retraction of the carrier 21. The latter is pivotally mounted on the member 17 for limited rotation in the vertical plane by means of a tilt ram 62 engaging the carrier via a ball 61 and slot 60. The carrier is also movable transversely of the support member 17 by means of a side-shift ram 19.

Dec. 3, 1968 v Filed Aug. '17, 1965 SCI 5 SORS EXTENDER B. 1. ULINSKI 3,414,150

5 Sheets-Sheet 1 Z0 Zl INVENTOR. 3O iwwsmus 1 UL/MS'K/ BY 4O f n 24 f Amway Dec. 3, 1968 B..l. ULINSKI SGISSORS EXTVENDER 5 Sheets-Sheet 3 Filed Aug. 17, 1965 INVENTOR. Beau/sums I. Van's/a P A Jada 4 8. l. ULINSKI SCISSORS EXTENDER Dec. 3, 1968 5 Sheets-Sheet 5 Filed Aug. 17, 1965 INVENTOR. Beau/anus Z. Mme/ 1 Dec. 3, 1968 a. ULlNSKl SCISSORS EXTENDER 5 Sheets-Sheet 4 Filed Aug. 17. 1965 l M i INVENTOR. Beau/8040s ZUL/NSK/ Z 64/4 Anonva Dec. 3, 1968 i B. ULlNSKl 3,414,150

scIss'ORs EXTENDER Filed Aug. 17, 1965 5 Sheets-Sheet 5 INVENTOR. Bfo/wsmus I Uu/rsm BY y xii-529% United States Patent 3,414,150 SCISSORS EXTENDER Bronislaus I. Ulinski, Jenkintown, Pa., assiguor to Eaton Yale & Towne, Inc., a corporation of Ohio Filed Aug. 17, 1965, Ser. No. 480,355 8 Claims. (Cl. 214-730) ABSTRACT OF THE DISCLOSURE A lift truck is equipped with two pairs of scissors links that support a load carrier for extending and retracting movement, each particular pair of links being formed from relatively thin metal plate, with one of its links formed in two parts. The two parts are arranged at opposed sides of the second scissors link of the particular pair, and are assembled to one another through a bearing member that is mounted to rotate in an opening of the second link. The scissors links will contribute a relatively large throw while each link is rather short, and will permit the truck operator better visibility. The load carrier supported by the scissors links has a hydraulic ram that will side shift load engaging forks, while also supporting the forks for both side shifting and vertical tilting movements.

This invent-ion relates to a lift truck having a scissors mechanism for projecting and retracting a plate that supports forks. The plate is projected and retracted relatively to a base member which is part of a load carriage and is moved upwardly and downwardly on the channels of uprights forming part of the truck.

In mechanisms of the particular class it is highly desirable that the visibility of the operator be impaired as little as possible through the mounting of the link constituting the scissors mechanism. Obviously, if the scissors mechanism uses wide levers, the visibility of the operator is seriously impaired, as those skilled in the art will appreciate.

It is further very important that the throw or movement of the forks be as long as possible while utilizing the shortest possible links as part of the scissors mechanism. Much effort has been expended by inventors of the prior art in an attempt to secure greater and greater throw with shorter and shorter links, and a patent well illustrating the efforts of the inventors of the prior art is that to Gibson, No. 3,082,894.

With this understanding of the prior art, those skilled in that art will readily recognize the very considerable contribution of this application. Thus, I have conceived an extremely novel type of bearing relationship between the links of my scissors mechanism, so that I obtain excellent bearing relationship between the links while utilizing simple plate metal for the formation of the links. As a particular feature of the invention, one of the links is formed of two parts that are assembled, one at each side of the other link, while pivotally mounted relatively to the other link, all by an extremely novel bearing.

In order to obtain the greatest amount of throw possible through use of my links, I have arranged it so that the pivots or other bearings between the links and the usual fork carrying plate move rearwardly of the points where the links are mounted on the base plate or carriage. In other words, the points of actuation of the fork carrying plate are rearward of the supports for the links on the carriage when the fork carrying plate is in a retracted position.

As a still further feature of the invention, and which feature is of very considerable merit, I mount the support for the forks of my invention on a bearing member that Patented Dec. 3, 1968 'ice is preferably slideable on a sideshift ram. Then, through operation of this arm, I am able to shift my fork support sideways of the truck. The fork support is integral with the bearing member. Obviously, by supplying fluid to the ram cylinder, the fork support is side shifted, Further, because the fork support is so carried by the ram cylinder, it may rotate on the axis of the cylinder for tilting the forks. This tilt is effected by rams, the operating ends of which bear against the fork support as it is shifted.

A further feature of the invention relates to the positioning of the operating rams for the scissors mechanism between one of the links and the moving support member. This mounting is quite effective as it then leaves an open space at the carriage, contributing greater visibility.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows maybe better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of my invention, in order to prevent the appropriation of my invention by those skilled in the art.

Referring to the drawings:

FIGURE 1 is an elevation of a standard type of industrial truck showing the attachment of my invention applied thereto.

FIGURE 2 is a partial section in elevation showing the scissors mechanism of my invention in a retracted position in which the support member is fully retracted.

FIGURE 3 is a view exactly like FIGURE 2 with the exception that the tilt .ram has been actuated to tilt the forks.

FIGURE 4 is a view similar to that of FIGURES 2 and 3 except that the scissors links have been operated to project the support member and showing the forks in a nontilted position and in a tilted position.

FIGURE 5 is an elevation in partial section taken vertically parallel to the lifting uprights of the truck and showing the relationship of the scissors links to one another and to the base plate and support member of my invention.

FIGURE 6 is a view looking downwardly on the parts of FIGURE 2 showing the relationship of the various parts of my scissors assembly.

FIGURE 7 is a section along the line 7-7 of FIG- URE 4.

FIGURE 8 is an exploded isometrical view of my invention but showing the relationship of scissor parts thereof.

Referring now more particularly to the drawings, reference number 10 refers to a standard type of industrial truck such as is well known in the art, and which utilizes primary uprights 11 that are fixed to the truck or are pivoted at the bottom end to the truck. As frequently happens in the trucks of the particular class, high lifting is desired, and for this purpose I utilize secondary uprights 12, which are probably better shown in such figures as 2 and 5. The secondary uprights move vertically on the primary uprights in the standard manner such as is well understood and which need not be described in detail here.

The invention of this application resides in an assembly of scissors links together with a base plate on a support member, in addition to other means. The base plate of my invention is designated by reference number 13 and comprises a pair of main side plates 14, each of the side plates having an upper roller 15 and a lower roller 16. These rollers ride in the channels of secondary uprights so that the base plate 13 may move upwardly and downwardly relatively to the secondary uprights and also move with the secondary uprights relatively to the primary uprights.

The support member of my invention comprises basically a pair of side plates 17a and 17b which are preferably joined together for integral movement by suitable transverse connecting bars 17d, 17c. A hydraulic ram cylinder 18 is fixed at each end thereof to the side plates 17a and 17b. The piston 19 of the hydraulic sideshift ram slides relatively to the plates 17 of the support memher and relatively to the cylinder 18. The piston 19 extends outwardly at both sides of the ram 18 and is secured at its ends 20 to what I term a load carrier 21. This load carrier 21 is adapted to carry load forks 22 which may be applied to the carrier through portions 23 coacting with a castellated edge 24 of the carrier 21. The carrier 21 is slideably supported on the external surface of cylinder 18 by a bearing housing 21a fixed to the carrier 21.

The piston 19 is formed with a piston head 25 as shown in FIGURE 8 which moves within the ram cylinder 18 through the introduction of fluid at 26 or at 27 and with the exit of fluid through the opposite opening 26 or 27. Thus, when the sideshift ram is actuated, the carrier bearing housing 21 is moved relative to the ram cylinder 18 and the load carrier is moved laterally relative to the support member. This constitutes what is termed sideshift to the load carrier 21 and forks 22. As those skilled in the art will well appreciate, there are many prior art concepts showing sideshifting mechanisms. However, as those skilled in the art will recognize the particular concept of moving a load carrier on and relatively to the ram cylinder in the manner conceived by me is particularly valuable within the load manipulating combination that I have so far outlined and which will be described in more detail presently.

Returning now to the main side plates 14 and side plates 17 of the support member, I shall describe the scissors mechanism interconnecting these plates, while referring only to the scissors links at one side of the truck. Thus, there are two pairs of scissors links, but since they are duplicates, I shall describe their construction through use of terms in the singular wherever possible and shall refer from one pair of scissors links to the other as seems more convenient in view of the arrangement of the drawings. Referring now more particularly to the FIGURE 8, it will be noted that one of each pair of links is designated by reference number 30. The upper end of this link carries a roller 31 which operates in a slot 32 of the main side plate 14. The lower end of the link is pivoted at 33 to its vertical plate 17. It will be noted that the link 30, as probably best seen in FIG- URE 5, has a central portion 34 and an offset upper portion 35 and a lower offset portion 36. Because of this particular arrangement, it will be obvious that the lower end 36 lies in a plane laterally spaced from that of the upper end 35 which carries the roller 31. Therefore, the lower end 36 can bypass the plate 14 and move from the projected position shown in FIGURES 4 and 8 to the retracted position shown in FIGURES 2 and 3.

The other link 30a of the scissors link combination of which link 30 is a component, is formed of two parts, one of which I designated by reference number 40 and the other by reference number 41. The two link parts 40 and 41 are assembled to one another and to a bearing 42 in a rather unique manner. Thus, it will be noted particularly from FIGURES 7 and 8 that the link 30 has a bearing opening 43 within which fits the bearing 42. Each of the link parts 40 and 41 is formed with a series of bored holes 44 aligned with bored holes 45 of the bearing 42. Obviously, through the use of bolts 46 the link parts 40, 41 may be assembled to one another as well as to the link 30. This locates the link part 41 to one side of the link 30 and the link part 40 to the other side of the link 30. It also very effectively mounts the two link parts 40 and 41 for rotation in the link 30 even though the link 30 is formed of relatively thin metal with the bearing opening 43 within the link portion 34. The location of the two link parts 40, 41 at each side of the link 30 gives effective support against twist to the bearing 42 while naturally, the bearing 42 secures the link parts 40, 41 together. As will be apparent, particularly from FIGURE 5, the link part 41 is offset relatively to the link part 40 in exactly the same manner as the link parts 35 and 36 of the link 30 are offset. This makes it possible for the upper portion of the link part 41 to carry a roller movable in a slide 47 of the plate 17 while the lower link portion 40 is pivoted at 48 to the plate 14. It will be quite evident from FIGURE 5 that the various link parts may effectively pass one another. Thus, the upper ends of the one-piece links 30 and the two-piece links 30:: are offset relatively to one another so that they can pass one another in either direction of movement and with-out hindrance. It will be obvious that the lower ends may also pass one another in either direction and without hindrance. Because of this, it is possible to obtain a very full projection and retraction of the support member constituting plates 17. This will be particularly appreciated as a study is now made of FIGURES 2, 3 and 4. In FIGURE 4, the plates 17 of the support member are shown projected relatively to the base plate through the action of the scissors mechanism. In FIGURES 2 and 3 the support plates 17 are shown fully retracted, and it will be noted that the pivot 33 is now at the rear of the pivot 48. In other words, because of this offset position, the pivot 33 is able to move not only to a position opposite to lever 40 but to a position at the rear of the base plate 14. This means that the scissors links have a greater throw than links of the usual scissors mechanism, because the throw can start from a more fully retracted position. It will also be noted in FIGURES 2 and 3 that the rollers 48a at the upper ends of the link parts 41 are rearward of the rollers 31, all in accordance with the teachings I have already set forth above.

It will now be understood that because of the construc tion of the links constituting my scissors mechanism, and because of the particular relationship described, I not only may use links formed of plates so as to contribute extreme visibility, but I am also able to effect a bypassing relationship that will contribute to the extremely effective throw and retraction of my support member and the load carrier.

The contribution of my invention further includes a novel arrangement of rams for effecting the throw of the support member plates 17, 17 relatively to the base plates 14, 14. For this purpose, each of the links 30 is formed with an abutment carrying a pivot 50 to which may be pivoted the piston 51 of a ram 52, the ram 52 is in turn pivoted at 53 to a plate 17. There are, naturally, two of these rams 52, one for each of the plates 17. It is through the extension and retraction of the rams 52 that the links are moved to throw and retract the support member. Through the mounting of the rams between the support member and the scissors links, I obtain a very effective result. Thus, I not only can contribute throw of the sup port member plates 17, but I do this without encumbering base plates 13 and its side plates 14. As those skilled will readily appreciate, the mounting of rams on the base plate or any part of the base plate, presents a very considerable problem particularly because it would be dilficult to operate the links without obstructing the movement of the support member into the closely nested position shown in FIGURES 2 and 3. I consider the mounting of the rams in the particular location to be a very effective and important element of the basically novel combination I herein set forth.

Because of the fact that the cylinder 18 operating in the bearing housing 21a is cylindrical, it may not only slide relatively to the cylinder 18, but may rotate relatively thereto. I take advantage of this rotation to elfect a pivotal movement of the load carrier 21 as will best be appreciated of FIGURES 2, 3, 4 and 8. Thus, the load carrier 21 and all slideable positions thereof, has a portion 60 that slides relatively to a ball 61 formed at the end 31 of tilt piston 62. There are two rams and two ram pistons 62, one at the bottom of each plate 17. Since in all positions the carrier 21 will bear against the roller 61 of each ram piston 62, it is merely necessary to project the ram piston 62 to effect tilt of the load carrier about the axis of the ram cylinder 18 and housing 21a.

While a preferred form of the invention has been shown and described, it will be appreciated that this is for the purpose of illustration and that changes and modifications may be made therein without departing from the spirit and scope of the invention.

I now claim:

1. In an industrial truck, a pair of uprights, a base plate, means mounting said base plate for vertical movement on said uprights, a support member, a pair of scissors links at each side of said base plate and support member, pivoted medially to one another and interconnecting said plate and member through pivots and slide hearings on said plate and member, so that as said links move pivotally relatively to one another the support member moves relatively to said base member while maintained in a vertical position, one of said links of each pair having a bearing opening intermediate its ends, a bearing member rotatably mounted in said opening, and the other link comprising two parts with one of said parts lying at one side of the first link and the other part lying at the other side of said first link, and each part having a fastening end overlying said bearing member, means securing said fastening ends to said bearing member whereby to assemble said link parts to said bearing member while simultaneously pivotally mounting said assembled link to said first link.

2. In an industrial truck, a pair of uprights, a base plate, means mounting said base plate for vertical movement on said uprights, a support member, a pair of scissors links at each side of said base plate and support member pivoted medially to one another and interconnecting said plate and member through pivots and slide bearings on said plate and member, so that as said links move pivotally relatively to one another the support member moves relatively to said base member while maintained in a vertical position, one of said links of each pair formed of relatively thin plate metal and having a bearing opening intermediate its ends, a bearing member rotatably mounted in said opening, and the other link comprising two parts formed of similar plate metal with one of said parts lying at one side of the first link and the other part lying at the other side of said first link, and each part having a fastening end overlying said bearing member, means securing said fastening ends to said bearing member whereby to assemble said link parts to said bearing member while simultaneously pivotally mounting said assembled link to said first link.

3. In an industrial truck, a pair of scissors links pivoted medially to one another, one of said links being formed of plate metal and having a bearing opening intermediate its ends, a bearing member rotatably mounted in said opening, and the other link comprising two parts with one of said parts lying at one side of the first link and the other part lying at the other side of said first link, and each part having a fastening end overlying said bearing member, means securing said fastening ends to said bearing member whereby to assemble said link parts to said bearing member while simultaneously pivotally mounting said assembled link to said first link.

4. In an industrial truck, a pair of uprights, a base plate, means mounting said base plate for vertical movement on said uprights, a support member, a pair of scissors links at each said of said base plate and support member, pivoted medially to one another and interconnecting said plate and member through pivots and slide bearings on said plate and member, so that as said links move pivotally relatively to one another the support member moves endwise relatively to said base plate while maintained in a vertical position, one of said links of each pair having a bearing opening intermediate its ends, and bent so that one of said ends is offset in one direction relatively to said bearing opening while the other end is ofiset in the opposed direction relatively to said bearing opening, a bearing member rotatably mounted in said opening, and the other link comprising two parts with one of said parts lying at one side of the first link and the other part lying at the other side of said first link, and each part having a fastening end overlying said bearing member, means securing said fastening ends to said hearing member whereby to assemble said link parts to said bearing member while simultaneously pivotally mounting said assembled link to said first link with the ends of said assembled link offset reversely to the ends of said first link.

5. In an industrial truck, a pair of uprights, a base plate, means mounting said base plate for vertical movement on said uprights, a support member, a pair of scissors links at each side of said base plate and support member, pivoted medially to one another and interconnecting said plate and member through pivots and slide bearings on said plate and member, so that as said links move pivotally relatively to one another the support member moves endwise relatively to said base member while maintained in a vertical position, one of said links of each pair having a bearing portion intermediate its ends, and shaped so that one of its ends is offset in one direction relatively to said bearing portion while the other end is offset in the opposed direction relatively to said bearing portion, and the other link comprising two parts with one of said parts lying at one side of the first link and the other part lying at the other side of said first link, and means assembling said link parts to said bearing portion and pivotally mounting said assembled link to said first link with the ends of said assembled link oflFset reversely to the ends of said first link.

6. In an industrial truck, a pair of uprights, a base plate, means mounting said base plate for vertical movement on said uprights, a support member, a pair of scissors links at each side of said plate and support member, pivoted medially to one another and interconnecting said plate and member through pivots and slide bearings on said plate and member, so that as said links move pivotally relatively to one anotherI-the support member moves endwise relatively to said base member while maintained in a vertical position, one of said links of each pair having a bearing portion intermediate its ends, and the other link comprising two parts with one of said parts lying at one side of the first link and the other part lying at the other side of said first link, and means assembling said link parts to said bearing portion and pivotally mounting said assembled link to said first link.

7. In an industrial truck, a pair of uprights, a base plate, means mounting said base plate for vertical movement on said uprights, a support member, a pair of scissors links at each side of said base plate and support member pivoted medially to one another with each link interconnecting said plate and member through one pivot bearing and one slide bearing so that as said links move pivotally relatively to one another the support member moves endwise relatively to said base member while maintained in a vertical position, one of said links having a bearing intermediate its ends and bent so that its opposed ends are offset relatively to said bearing, and the other link comprising one part lying at one side of the first link and another part lying at the other side of the said first link,

means fastening said parts to one another in bearing relation to said bearing whereby to assemble said other link parts to said first link while simultaneously pivoting said assembled link to said first link with the opposed ends of said assembled link also in offset relation.

8. In an industrial truck, a pair of operating scissors links, one of said links having a bearing opening intermediate its ends and bent so that the opposed ends are offset, a bearing member rotatably mounted in said opening, and the other link comprising two parts with one of said parts lying at one side of the first link and the other part lying at the other side of said first link, and each part having a fastening end overlying said bearing member, means securing said fastening ends to said bearing member whereby to assemble said link parts to said bearing member while simultaneously pivoting said assembled link to said first link while positioning the opposed ends of said assembled link also in offset relation.

References Cited UNITED STATES PATENTS 2,752,058 6/1956 Gibson 2l4730 3,048,293 8/1962 Cushman 2l4730 3,036,865 5/1962 Stone 298l1 ALBERT J. MAKAY, Primary Examiner. 

